How do we know self-righteousness is dangerous?

Self-righteousness is a significant danger that stems from a misplaced reliance on one's own works to gain God's favor. The sermon illustrates this through the parable of the Pharisee and the tax collector, where the Pharisee boasts about his supposed righteousness while the tax collector humbly asks for mercy (Luke 18:9-14). This self-righteous attitude is hypocrisy because it presents a façade of goodness without acknowledging the true spiritual condition of the heart—a heart that is deceitful and wicked (Jeremiah 17:9). In essence, self-righteousness blinds individuals to their need for Christ, as they cling to their own performances instead of recognizing that all righteousness comes solely through faith in Jesus Christ, who alone can justify the ungodly.